Form Sumbit/validation

All I need it to do is check that at least one of 5 search fields has some info in it before it is submitted to a php page.

I'm using a button instead of a submit in html. The onClick = "check_submit()" does not work. I think it's a problem with the submit() method in the check_submit() function:

function check_submit(){
if (search_val1) {
alert("Order has been Submitted");
submit();
}
else {
alert("Sorry, Order Cannot Be Submitted!");
return false;
}
I've tried onClick = "check_submit(this.form)", submit(this.form) and submit(form name) in the function but nothing happens. I guess I'm using submit in the wrong way.